Hi, I recently rebuilt the top end of my sons KLX 300r (new valves,piston, gaskets,valve shims) everything is in time and the valves are shimmed in spec. the bike starts fine cold and runs great. the problem is when he shuts the bike down he cant it started for about 15-20 min. did i miss anything we didnt touch the carb (stock). i tried the idle mixture screw a couple of different positions,same thing happens. if anybody has any other ideas or has had the same problem i would appreciate some help. Thanks Bob Butler

 

probably the pick up clearance too big...

take the left cover of, the pick up is in there... kinda hard to measure..what you do..with screwdriver..bend it down a bit.. less then 0.5mm..
cover back on..turn the engine over.. you'll hear if the rotor scrapes.. then it was too much, if no noise.. its fine..